Formylvaleric acid and formylvalerate esters are valuable intermediates which are useful, for example, in the production of epsilon caprolactam. The processes currently used to produce formylvaleric acid and/or formylvalerate esters have various disadvantages. For example, the prior art processes to formylvaleric acid and/or formylvalerate esters exhibit catalyst stability problems. Also, formylvaleric acid and/or formylvalerate ester selectivities may not be as high as desired. Accordingly, it would be desirable to produce epsilon caprolactam precursors by a process which does not have the disadvantages of prior art processes.